January 29, 2007
Diagnosis and Symptoms
Question from Cullman, Alabama, USA:
My 10-year-old non-obese son had some symptoms of low blood sugar (headache, passing out, dizziness), which prompted his doctor to order a four hour glucose test. In that test, the second and third hour indicated high glucose levels and a small amount of blood spilling over into his urine. She told us to start checking his blood sugar at home. On December 26, 2006, his readings were high, 300 mg/dl [16.7 mmol/L], 394 mg/dl [21.9 mmol/L], 412 mg/dl [22.9 mmol/L], then HI. I took him to Children’s Hospital where he was admitted and diagnosed with type 1 diabetes. They said we caught it early and that he was in the honeymoon phase. They started him on four units of Levemir on the following day, but have been decreasing it every week because of low blood sugars; now, he is on only one unit.
Today, I got the results of the laboratory tests that were taken on the 26th. His A1c was 5.2; C-Peptide was 5.5; insulin antibody negative; and a GAD-65 of 0.5. The diabetic educator who took my call said she didn’t know how to read his test results and that we would have to wait until February 13, when we see the pediatric endocrinologist, to find out the meaning of these tests. To me, it doesn’t sound like he has type 1 diabetes and I don’t want to give him insulin if he doesn’t need it. I also want to be prepared to ask the right questions when we do see the endocrinologist. Do his results sound like type 1 or MODY? Can you have diagnosed type 1 diabetes so early and be in the honeymoon phase at the same time? Or, could this be something totally different that we should be investigating?
Answer:
This is a very odd story. It sounds like it could be the early phase of type 1 diabetes particularly with weakly positive GAD antibodies. We would usually repeat such a test and see if they persist or not, same with the negative islet cell antibodies. Some children have one and not the other for reasons still not explained. The decisions about insulin are somewhat philosophical with some scientific research suggesting staying on a small amount of insulin – as long as it does not cause symptomatic hypoglycemia – as a way to save the pancreas insulin production capacity by not having it overworked. There is some evidence from studies by John Malone about this many years ago. In any case, you should continue frequent blood sugar monitoring and stay in contact with your diabetes team to answer these questions for your child and not just on general terms. It does not sound like MODY, but there are also tests available for looking at MODY genes to help with the diagnosis if family history does not suggest MODY as a possibility.
SB
